Implementation of tactical maneuvers with maneuver libraries

This study creates and combines the general maneuver libraries for fixed-wing aircraft to implement tactical maneuvers. First, the generalized maneuver libraries are established by analyzing the characteristics of tactical maneuvers required in battlefields. The 7th order polynomial is applied to both the creation of the maneuver libraries and the generation of the trajectories or flight paths for modal inputs. To track the desired trajectory, we design the Attitude Command Attitude Hold (ACAH) system and the Rate Command Rate Hold (RCRH) system using Model Following Controller (MFC). Moreover, the Line-of-Sight (LOS) guidance law is designed. In particular, the CONDUIT® is employed to optimize the gains so that the control systems meet the aircraft Handling Qualities (HQ) criteria. Finally, flight simulations are performed for the longitudinal loop, immelmann-turn, and climb-slalom-descent maneuvers to verify that tactical aggressive maneuvers are realizable via the combination of maneuver libraries. This study can contribute to the development of flight techniques for aircraft tactical maneuvers and to the revision of air force operational manuals.     

S7-300液位控制系统下位机的实现

利用以太网,结合西门子现场总线搭建了过程控制平台,完成了对温度、压力、流量和液位这些典型过程参数的采集、存储和分析,并利用PID算法通过对变频器、电控阀门的控制,实现恒压供水任务,进而完成对于水箱液位稳定的控制.     

Relationship between daily variation of cosmogenic nuclide Be-7 concentration in atmosphere and solar activities

Daily Be-7 concentrations in air at the height of 15 m are continuously observed at 38°15.2′N, 140°20.9′E, between 2000 and 2001. The average concentration and the relative standard deviation were 4.0 mBq/m³ and 50% in 2000–2001, respectively. The Be-7 concentrations increased 2.5% with the decrease in the sunspot numbers by 6.7% for the term of two years. From the power spectral analysis, the periodicity of 26 days is shown for the daily Be-7 concentrations. The folding analysis indicates that the time variation of the Be-7 concentration is similar to that of the ground-based neutron counting rate, and the phase delay for the minimum portion of Be-7 concentration was roughly 8 days to the maximum sunspot number. These results indicate that the Be-7 concentrations in the air at ground level have 26 day periodicity as a component of time variations and the time variation is caused by the solar modulation of galactic cosmic rays, which corresponds to the variation of the sunspot number due to the rotation of the sun.     

为中国开发太空探路 创中国首飞太空记录——纪念T-7系列探空火箭首次发射成功45周年

在中国第一个实用探空火箭系列——T-7系列探空火箭首次发射成功45周年之际，回顾了该系列火箭的研制由来和基本情况，论述了该系列火箭对中国开发中层大气和太空所起到的探路作用。     

几种新型的星载多光谱和成像光谱仪

近几年出现了几种新型的星载多光谱和成像光谱仪,例如:Landsat-7卫星的有效载荷增强型主题测绘仪+（ETM+）;EOS AM-1卫星的有效载荷多角度成像光谱仪（MISR）和先进空间热发射和反射辐射计（ASTER）;特殊探测器紫外成像光谱仪（SSUSI）。文章从结构、性能参数等方面综述了这几种星载成像光谱仪。     

星载激光测高地面数据处理设计研究

星载激光测高技术是对地观测系统中最为核心和前沿的信息获取技术之一,因其具有探测方向性好、测距精度高等特点,在地球科学领域中体现出了巨大的应用潜力。在ICESat/GLAS测高地面数据处理系统的基础上,针对将于今年发射的高分七号卫星的载荷特点,设计了一套星载激光测高地面数据处理系统软件。该软件可实现对星载激光测高数据的地面处理并生成3级数据产品,包含激光能量计算、波形分解和激光脚点定位等,以及相应各级产品的数据质量控制处理。利用高分七号仿真数据对该软件进行相应的性能测试,测试结果表明:该系统软件基本满足需求,已初步具备星载激光测高地面数据处理能力。     

WP7系列发动机涡轮导向器叶片盖板的钎焊修复

采用真空钎焊的方法对WP7系列发动机涡轮导向器叶片盖板进行了修复,介绍了修复过程及工艺。修复后的叶片经目视及荧光检验未发现表面裂纹,该修复工艺已成功用于WP7系列发动机涡轮导向器叶片盖板的批量修复,年修复量约1000件。     

Ionospheric total electron content response to annular solar eclipse on June 21, 2020

The effects of physical events on the ionosphere structure is an important field of study, especially for navigation and radio communication. The paper presents the spatio-temporal ionospheric TEC response to the recent annular solar eclipse on June 21, 2020, which spans across two continents, Africa and Asia, and 14 countries. This eclipse took place on the same day as the June Solstice. The Global Navigation Satellite System (GNSS) based TEC data of the Global Ionosphere Maps (GIMs), 9 International GNSS Service (IGS) stations and FORMOSAT-7/COSMIC-2 (F7/C2) were utilized to analyze TEC response during the eclipse. The phases of the TEC time series were determined by taking the difference of the observed TEC values on eclipse day from the previous 5-day median TEC values. The results showed clear depletions in the TEC time series on June 21. These decreases were between 1 and 9 TECU (15–60%) depending on the location of IGS stations. The depletions are relatively higher at the stations close to the path of annular eclipse than those farther away. Furthermore, a reduction of about ?10 TECU in the form of an equatorial plasma bubble (EPB) was observed in GIMs at ~20° away from the equator towards northpole, between 08:00–11:00 UT where its maximum phase is located in southeast Japan. Additionally, an overall depletion of ~10% was observed in F7/C2 derived TEC at an altitude of 240 km (hmF2) in all regions affected by the solar eclipse, whereas, significant TEC fluctuations between the altitudes of 100 km ? 140 km were analyzed using the Savitzky-Golay smoothing filter. To prove TEC depletions are not caused by space weather, the variation of the sunspot number (SSN), solar wind (V_SW), disturbance storm-time (Dst), and Kp indices were investigated from 16th to 22nd June. The quiet space weather before and during the solar eclipse proved that the observed depletions in the TEC time series and profiles were caused by the annular solar eclipse.     

“微风”(Zephyr7)无人机机翼力学性能分析

利用ABAQUS有限元软件对英国的"微风"(Zephyr7)无人机机翼结构进行了静力学分析,重点分析了主梁直径和蒙皮张力对机翼结构抗弯性能的影响。分析结果表明,主梁的抗弯与抗扭性能随着其直径的增大呈几何级数提升,机翼抗弯性能随着其蒙皮张力的增加近似线性增加。